The document WO-A-2011/157915 describes a sealed and thermally insulating tank for the storage of liquefied natural gas, of the type which comprises a tank wall fixed to a flat bearing wall. The tank wall comprises a primary sealing membrane and a thermally insulating barrier disposed between the bearing structure and the primary sealing membrane. The primary sealing membrane essentially consists of a plurality of corrugated metal sheets tightly welded to one another which form a first series of equidistant parallel rectilinear corrugations extending in a first direction of the plane of the bearing wall and a second series of equidistant parallel rectilinear corrugations extending in a second direction of the plane of the bearing wall, the second direction being at right angles to the first direction, the distance between two adjacent corrugations of the first series and the distance between two adjacent corrugations of the second series being equal to a predetermined corrugation interval. The corrugated metal sheets have rectangular forms whose sides are parallel to, respectively, the first direction and the second direction of the plane of the bearing wall and whose dimensions are substantially equal to integer multiples of the corrugation interval, each edge of a corrugated metal sheet being situated between two adjacent corrugations parallel to said edge.
WO-A-2011/157915 proposes structures that allow the passage of a support foot through the bottom wall of the tank. However, when a diameter of the support foot exceeds two corrugation intervals, these structures provide for locally shifting the routing of the corrugations to form more complex networks of corrugations. Now, increasing the complexity of the network of corrugations in this way can prove complicated to implement, particularly in the case where the routing of the corrugations has an effect on other elements of the tank wall, which must then be adapted to the more complex networks of corrugations. These considerations notably come into play when seeking to design the secondary membrane disposed between the primary insulating barrier and the secondary insulating barrier in the form of a corrugated metal membrane.
Similar problems are also likely to arise in the top wall of the tank, for example in a vapor-collecting duct or in the bottom wall of the tank, for example in a sump structure or any other element passing through a singular zone of the tank wall.